大肠癌是常见恶性肿瘤之一,在消化道癌中位居第三,不仅发病率高,且有连年上升趋势。由于起病隐匿,早期常无明显临床表现,故极易延误诊断和治疗,严重地威胁着人类健康。然而,本病的确切病因至今尚未完全清楚。不过,肿瘤细胞与其它细胞的主要区别在于其具有无限增殖能力;而端粒酶 Colorectal cancer is one of the common malignant tumors, ranking the third in gastrointestinal cancer, not only in high incidence, but also in successive years. Due to occult onset, often no obvious early clinical manifestations, it is extremely easy to delay diagnosis and treatment, a serious threat to human health. However, the exact cause of this disease has not yet been fully understood. However, the major difference between tumor cells and other cells is their ability to proliferate indefinitely; whereas telomerase